TGFB1 and neoplasm: Interestingly, TGF-β stimulated the expression of secreted proteins, including Pdgfa, Pdgfb, Wnt7a, and Wnt7b, all of which could activate surrounding mesenchymal cells, indicating that EMT is occurring in conjunction with alterations in the tumor microenvironment and involves reciprocal interactions between tumor and stromal cells.